The present invention relates to an article transfer apparatus for continuously receiving identical articles such as coiled filaments held in a feeding unit such as a vibrating bowl feeder and for transferring them to an article assembling station with a feeding mechanism.
The article assembling station comprises a filament mounting machine in an automatic manufacturing system of light bulbs for an electric lamp or a fluorescent lamp when the article is a coiled filament. With the intermittent operation of the article transfer apparatus, filaments are transferred to the filament mounting machine one by one.
A vibrating bowl feeder which randomly stores coiled filaments is disclosed in U.S. Pat. Nos. 3,106,181; 3,115,233; 3,200,965 and 3,207,287. Among these U.S. patents, in U.S. Pat. No. 3,207,287, a vibrating bowl feeder has a structure wherein each of filaments stored in the vibrating bowl feeder is fed from the feeder through a chute which is inclined downward along the transfer direction, and is transferred to a feeding mechanism of a mounting machine disposed therebelow in response to an intermittent operation of the feeding mechanism, that is, an index operation thereof. A plurality of shutter members which temporarily hold the descending filament are disposed at the chute. The shutter members selectively repeat opening/closing operation in accordance with the assembling operation so as to sequentially feed the filaments. Since the smooth surface of the chute is relatively long, a plurality of shutter members are preferably incorporated to control the position and orientation of the filament descending on the chute. However, the plurality of shutter members may result in the complicated structure of the apparatus and the sophisticated operation control therefor.
On the other hand, when shutter members are disposed only at the inlet port side of the chute and are free to open in response to the index operation of the feeding mechanism of the article assembling station, the following problem is presented. As described above, since the smooth surface of the chute must be relatively long, the descending time of the filament is prolonged. When dust is attached to the surface of the chute or the surface thereof is contaminated, the descending time of the filaments becomes irregular. This irregular descending time results in mismatch with the index timing of the feeding mechanism. When the above problem is considered, the high speed operation of the apparatus is hardly achieved.
In the conventional article transfer apparatus, since the opening/closing operation of the shutter members is generally synchronous with the timing of the index operation of the feeding mechanism of the article assembling station, the shutter member may close even if the operation for feeding the filament is not actually completed. If this occurs, the filament is clamped by the shutter. As a result, a trouble occurs in smooth filament feeding and the filament may fly away. This problem is attributable to the fact that the opening/closing operation of the shutter member is independent of the actual operation for feeding the filaments.
In the conventional article transfer apparatus, a typical example of which is U.S. Pat. No. 3,207,287, the filament descends along the smooth surface of the chute, as if the filament rolls down thereon, remaining transversely thereon, that is, with its longitudinal axis being perpendicular to the feeding direction.
In an article transfer apparatus of this type, if proper inclination of the smooth surface is established, the filament rolls down thereon by its weight. Thus, this arrangement has an advantage in that special vibrating feeder means is not required. However, the position and orientation of the filament which is rolling down on the smooth surface are unstable. Therefore, a plurality of shutter members must be disposed at equal intervals on the smooth surface of the chute. Further, the filament descending time is hardly shortened.